Nuclear radiation shields, shielding systems and associated methods

Abstract

A radiation shield, which may attenuate nuclear radiation or ionizing particles, may include a non-toxic, radioactivity-attenuating material based on an element or an elemental species having an atomic number of 56 or more. Examples of such materials include barium sulfate and bismuth oxide. A radiation shield may include two or more different radioactivity-attenuating materials, which may attenuate different types of nuclear radiation or ionizing particles, or attenuate different energy ranges of nuclear radiation or ionizing particles. Different radioactivity-attenuating materials may be carried by different layers of the radiation shield. Radiation shields with at least partially superimposed layers are also disclosed. Adjacent layers of such a radiation shield may be able to move longitudinally relative to one another, or slide somewhat relative to each other. Any of these features may be incorporated into a blanket, a protective suit or other protective garment, tape or any other configuration of radiation shield. Pliable radiation shields that attenuate nuclear radiation or ionizing particles are also disclosed, as are methods for limiting exposure to nuclear radiation or ionizing particles.

What is claimed: 
     
         1 . A nuclear radiation shield, comprising:
 a shell defining an exterior of the nuclear radiation shield and an interior of the nuclear radiation shield; and   a radioactivity-limiting element within the interior defined by the shell, the radioactivity limiting element including:
 of at least one non-toxic, radioactivity-attenuating material based on an element or an elemental species or compound having an atomic number of 56 or greater; and 
 a polymer holding the particles together, the polymer arranging the particles in a configuration that limits passage of nuclear radiation or ionizing particles through the radioactivity-limiting element. 
   
     
     
         2 . The nuclear radiation shield of  claim 1 , wherein the radioactivity-limiting element includes a plurality of superimposed layers, each layer of the plurality of superimposed layers including a polymer and particles of the at least one non-toxic, radioactivity-attenuating material carried by the polymer. 
     
     
         3 . The nuclear radiation shield of  claim 2 , wherein the plurality of layers of the radioactivity-limiting element comprises layers that include different non-toxic, radioactivity-attenuating materials. 
     
     
         4 . The nuclear radiation shield of  claim 3 , wherein the different non-toxic, radioactivity-attenuating materials attenuate ionizing nuclear radiation or particles of different energies. 
     
     
         5 . The nuclear radiation shield of  claim 4 , wherein a first non-toxic, radioactivity-attenuating material of a first layer of the plurality of layers comprises barium sulfate and a second non-toxic, radioactivity-attenuating material of a second layer of the plurality of layers comprises bismuth oxide. 
     
     
         6 . The nuclear radiation shield of  claim 1 , wherein the radioactivity-limiting element enables a smaller dose of nuclear radiation or ionizing particles to pass therethrough than a dose of nuclear radiation or ionizing particles that pass through a lead barrier with a same thickness as the radioactivity-limiting element. 
     
     
         7 . The nuclear radiation shield of  claim 6 , wherein the radioactivity-limiting element weighs less than a lead barrier having the same dimensions. 
     
     
         8 . The nuclear radiation shield of  claim 1 , wherein the radioactivity-limiting element resists cracking. 
     
     
         9 . The nuclear radiation shield of  claim 8 , wherein the radioactivity-limiting element is flexible. 
     
     
         10 . The nuclear radiation shield of  claim 1 , wherein the shell and the radioactivity-limiting element form a radioactive protective blanket. 
     
     
         11 . A shield for attenuating nuclear radiation or ionizing particles, comprising:
 a plurality of layers that are at least partially superimposed relative to one another and that are enabled to move longitudinally relative to one another; and   a radioactivity-attenuating material in at least one layer of the plurality of layers.   
     
     
         12 . The shield of  claim 11 , wherein the ability of the plurality of layers to move longitudinally relative to one another imparts the shield with flexibility. 
     
     
         13 . The shield of  claim 12 , wherein each layer of the plurality of layers is flexible. 
     
     
         14 . The shield of  claim 13 , wherein the radioactivity-attenuating material comprises a non-toxic, radioactivity-attenuating material based on an element or an elemental species having an atomic number of 56 or greater. 
     
     
         15 . The shield of  claim 14 , wherein particles of the radioactivity-attenuating material are carried by a polymer of the at least one layer. 
     
     
         16 . The shield of  claim 15 , wherein the particles of the radioactivity-attenuating material are held together or dispersed in the polymer. 
     
     
         17 . The shield of  claim 11 , wherein the plurality of layers comprises at least twenty layers. 
     
     
         18 . The shield of  claim 17 , wherein the plurality of layers comprises up to thirty layers. 
     
     
         19 . The shield of  claim 11 , further comprising:
 a shell for carrying the plurality of layers.   
     
     
         20 . The shield of  claim 11 , wherein the plurality of layers comprises a plurality of layers of pliable material or flowable material. 
     
     
         21 . A shield for attenuating nuclear radiation or ionizing particles, comprising:
 a first radioactivity-attenuating material for attenuating nuclear radiation or ionizing particles having a first range of energies; and   a second radioactivity-attenuating material for attenuating nuclear radiation or ionizing particles having a second range of energies, the second range of energies differing at least partially from the first range of energies.   
     
     
         22 . The shield of  claim 21 , wherein the first radioactivity-attenuating material comprises or is based on an element or an elemental species with a first atomic number and the second radioactivity-attenuating material comprises or is based on an element or an elemental species with a second atomic number, the first atomic number being smaller than the second atomic number. 
     
     
         23 . The shield of  claim 22 , wherein the first radioactivity-attenuating material is located to be positioned closer to a source of nuclear radiation or ionizing particles than the second radioactivity-attenuating material. 
     
     
         24 . The shield of  claim 23 , further comprising:
 a shell with an interior for carrying the first radioactivity-attenuating material and the second radioactivity-attenuating material.   
     
     
         25 . The shield of  claim 24 , wherein shell includes a top surface and a bottom surface that are visibly distinguishable from one another. 
     
     
         26 . The shield of  claim 25 , wherein the first radioactivity-attenuating material is positioned closer to the bottom surface of the shell than the second radioactivity-attenuating material and the second radioactivity-attenuating material is positioned closer to the top surface of the shell than the first radioactivity-attenuating material. 
     
     
         27 . The shield of  claim 21 , wherein the first and second radioactivity-attenuating materials comprise superimposed elongated flexible strips that form a tape. 
     
     
         28 . A material for attenuating nuclear radiation or ionizing particles, comprising:
 a pliable component configured to be molded into a shape and retain the shape; and   at least one radioactivity-attenuating material dispersed throughout the pliable component.   
     
     
         29 . The material of  claim 28 , wherein the pliable component is configure to adhere to a substrate. 
     
     
         30 . The material of  claim 28 , wherein the pliable component comprises a putty. 
     
     
         31 . The material of  claim 28 , wherein the at least one radioactivity-attenuating material comprises a non-toxic, radioactivity-attenuating material based on an element or an elemental species having an atomic number of 56 or more. 
     
     
         32 . A material for attenuating nuclear radiation or ionizing particles, comprising:
 a flowable component configured to be applied to coat a substrate; and   at least one radioactivity-attenuating material dispersed throughout the flowable component.   
     
     
         33 . A method for limiting a dosage of nuclear radiation or ionizing particles to which an individual is exposed, comprising:
 positioning a low Z radioactivity-attenuating material between a source of radioactivity and the individual to absorb incident nuclear radiation or ionizing particles from the source; and   positioning a high Z radioactivity-attenuating material between the low Z radioactivity-attenuating material and the individual to absorb secondary ionizing radiation from the low Z radioactivity-attenuating material.   
     
     
         34 . The method of  claim 33 , wherein positioning the low Z radioactivity-attenuating material and positioning the high Z radioactivity-attenuating material comprises:
 placing a radiation shield including the low Z radioactivity-attenuating material and the high Z radioactivity-attenuating material between the source and the individual; and   orienting the radiation shield with the low Z radioactivity-attenuating material being located closer to the source than the high Z radioactivity-attenuating material.   
     
     
         35 . The method of  claim 33 , wherein positioning at least one of the low Z radioactivity-attenuating material and the high Z radioactivity-attenuating material comprises securing a pliable or flowable material to a substrate.